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Ohio

What percentage of organic matter do you guys feel comfortable with in your patch. Reason I ask is because there is a big window here that I have been seeing that growers are growing huge pumpkins whether it be low or sky high,,,,,DON YOUNG!,lol

12/11/2007 4:53:20 AM

Windsor, Ontario, Canada

I've seen some trends that would lead me to believe that a very high OM percentage, say 15+, can lead to severe splitting problems. I am trying to reach somewhere in the neighborhood of 12-13.

Even with 12-13, there is not likely any need for additional fertilizer applications.

12/11/2007 8:33:47 AM

me ive been higher than most-keep things balanced i think is key -at a certain point excess is just over kill plant can only use so much

12/11/2007 9:16:50 AM

Mill Bay, British Columbia

Jordan, there is no way to tell what your npk ratios are without a soil test no matter what your organic matter content is so your last statement is rather misleading.

I had 18% organic matter last spring yet my soil test came back low on nitrogen from both tests. Now my fall soil test has come back still high on the organic matter scale but now low on the potassium.

Brooks, I've had reports as high as 28% OM (way over-did the ammendment thing a few years back) but on the advice of a wise mentor, have backed off and things have settled down now to around 15-18% and my soil has never looked better.

12/11/2007 10:55:12 AM

Cincinnati,OH

What was your OM Brooks? Mine was 9.5%

12/11/2007 8:00:23 PM

Picton,ON (j.vincent@xplornet.ca)

I think it depends a lot on soil type. Clay soils need to be raised to a higher OM content in order to provide adequate tilth.

Another issue is OM stability. OM is tested in the lab by burning the sample, so it takes into consideration not only the real "organic matter" but also the not fully decomposed organic material present in the sample. For example, our OM test dropped 2% year over year because of decomposition. Stable fully decomposed OM will not move this much in one season.

Our target here is build to and maintain 10-12%

12/11/2007 9:58:45 PM

Windsor, Ontario, Canada

Ok, heres a question, if you raised the OM in a clay soil, wouldn't it cease to be the same clay soil. More OM means a change in soil type doesn't it?

12/11/2007 11:35:50 PM

Picton,ON (j.vincent@xplornet.ca)

No and yes Jorden. OM will change soil structure! The amount of sand, silt and clay make up a soils texture. You can't change texture unless you alter the amount of Sand, silt or clay content. A high OM clay soil will act differently than a low OM clay soil. You are also correct about CEC. OM is part of the calculation to determine CEC (it's not a test folks). and you can alter CEC over time by raising OM. In general terms Sandy soils are low CEC and clays are high.

12/12/2007 8:14:32 AM

Picton,ON (j.vincent@xplornet.ca)

Our soil here is a silty clay. It packs over the summer with traffic and irrigation. This tightens the ‘A’ horizon and reduces the ability of the roots to move freely as well as reducing their ability to get nutrients. We are trying to counter this by adding lots of OM as well this year I added a significant amount of sand. Theoretically, this will change my texture. This will also lower my PH, CEC and Calcium content. One of the key points to changing texture, is making sure amendments are properly mixed. This can be very difficult. Especially in a garden situation.

12/12/2007 8:20:47 AM

Ontario, Canada.

Brooks the low numbers are what is surprising to most of us over the last few years.

John raises several good points it depends upon your soil type. I like my clay soil & CEC higher approaching 20%, but does it really matter much. Apparently not.

On the cruise last year I had an HH tell me anything over 6% usually provides enough stored quantities of N and all other nutrients. I believe it now espcially after seeing the soil test reports from the SNGPG newsletter.

Unless you grow in Muck soil the natural background OM is usually between 3 to 5 % so an extra 1 % doesn't seam like that much. However the proof is out there, that these things will do fine in the 6 to 10 range and still produce a 1600 pound-er.

12/12/2007 9:18:36 AM

southwest MO

Maybe these more native OM% and nutrient levels are playing a role in making the plant work a bit. Maybe these small enviromental stressors are triggers for hormonal and other responses from the plant that make it stronger and may indeed be nessecary to make the plant as strong as it can be and grow to FULL potential.

12/12/2007 10:05:57 AM